The present study was aimed at examining the relationships between affective status, mood, and stress in both a psychiatric patient group (n = 100) and a healthy volunteer group (n = 101 persons), as well as trying to find evidence of a gender effect. The Positive Affect (PA) and Negative Affect (NA), Stress and Energy (SE), Dispositional optimism (LOT), Comprehensive Psychopathological Rating Scale (CPRS) self-rating scale and the DSM- IV and ICD-10 Personality Questionnaire (DIP-Q) were used. Psychiatric disability had a detrimental effect on stress, energy, and optimism. The results indicated that stress was predicted by NA and that PA was counterpredictive for stress. Different effects were found for males and females, with NA predicting stress for both men and women, while the DIP-Q general criteria were stress predictors for males only and PA was counterpredictive for stress in men. Stress as a dependent variable was not significantly predicted by either DIP-Q general criteria, CPRS-depression, CPRS-compulsion, or CPRS-anxiety. It was predicted by negative affect and counterpredicted by positive affect. Data suggest that negative affect was the most important factor in predicting stress. The healthy volunteer group was found to be less affected by stress than the psychiatric patient group.